That's recently been narrowed down to 98.7% and really only applies to microorganisms, definitely not the definition used for species with sex. Furthermore, the DNA-DNA hybridization technique is considered outdated at this point so one has to take it with a grain of salt. Also, viruses aren't even organisms so I'm not really sure you can even talk about species with them. I have heard the term quasispecies used for them however.